Abstract A modular synthesis of photoactivable cross-linking agents is described, using an aromatic core, di- or triethyleneglycol spacers and photoaffinitylabeling synthons that feature either perfluorophenylazide or aryl(trifluoromethyl)diazirine motifs. Symmetrical and nonsymmetrical trivalent structures were obtained from phloroglucinol and dopamine, respectively. Symmetrical tetravalent structures